Re: [PATCH v3] rtc: ds1307: Add driver for Epson RX8901CE

[kernel test robot <lkp@intel.com>]

Hi Fredrik,

kernel test robot noticed the following build warnings:

[auto build test WARNING on dc59e4fea9d83f03bad6bddf3fa2e52491777482]

url:    https://github.com/intel-lab-lkp/linux/commits/Fredrik-M-Olsson/rtc-ds1307-Add-driver-for-Epson-RX8901CE/20260629-232253
base:   dc59e4fea9d83f03bad6bddf3fa2e52491777482
patch link:    https://lore.kernel.org/r/20260629-ds1307-rx8901-add-v3-1-302dc3cbb71e%40axis.com
patch subject: [PATCH v3] rtc: ds1307: Add driver for Epson RX8901CE
config: hexagon-allmodconfig (https://download.01.org/0day-ci/archive/20260630/202606300521.DkMaPRKi-lkp@intel.com/config)
compiler: clang version 23.0.0git (https://github.com/llvm/llvm-project 6cc609bb250b21b47fc7d394b4019101e9983597)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260630/202606300521.DkMaPRKi-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202606300521.DkMaPRKi-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/rtc/rtc-ds1307.c:2332:2: warning: label at end of compound statement is a C23 extension [-Wc23-extensions]
    2332 |         }
         |         ^
   1 warning generated.


vim +2332 drivers/rtc/rtc-ds1307.c

  2066	
  2067	static int ds1307_probe(struct i2c_client *client)
  2068	{
  2069		const struct i2c_device_id *id = i2c_client_get_device_id(client);
  2070		struct ds1307		*ds1307;
  2071		const void		*match;
  2072		int			err = -ENODEV;
  2073		int			tmp;
  2074		const struct chip_desc	*chip;
  2075		bool			want_irq;
  2076		bool			ds1307_can_wakeup_device = false;
  2077		unsigned char		regs[8];
  2078		struct ds1307_platform_data *pdata = dev_get_platdata(&client->dev);
  2079		int			trickle_charger_setup = 0;
  2080	
  2081		ds1307 = devm_kzalloc(&client->dev, sizeof(struct ds1307), GFP_KERNEL);
  2082		if (!ds1307)
  2083			return -ENOMEM;
  2084	
  2085		dev_set_drvdata(&client->dev, ds1307);
  2086		ds1307->dev = &client->dev;
  2087		ds1307->name = client->name;
  2088	
  2089		ds1307->regmap = devm_regmap_init_i2c(client, &regmap_config);
  2090		if (IS_ERR(ds1307->regmap)) {
  2091			dev_err(ds1307->dev, "regmap allocation failed\n");
  2092			return PTR_ERR(ds1307->regmap);
  2093		}
  2094	
  2095		i2c_set_clientdata(client, ds1307);
  2096	
  2097		match = device_get_match_data(&client->dev);
  2098		if (match) {
  2099			ds1307->type = (uintptr_t)match;
  2100			chip = &chips[ds1307->type];
  2101		} else if (id) {
  2102			chip = &chips[id->driver_data];
  2103			ds1307->type = id->driver_data;
  2104		} else {
  2105			return -ENODEV;
  2106		}
  2107	
  2108		want_irq = client->irq > 0 && chip->alarm;
  2109	
  2110		if (!pdata)
  2111			trickle_charger_setup = ds1307_trickle_init(ds1307, chip);
  2112		else if (pdata->trickle_charger_setup)
  2113			trickle_charger_setup = pdata->trickle_charger_setup;
  2114	
  2115		if (trickle_charger_setup < 0)
  2116			return trickle_charger_setup;
  2117	
  2118		if (trickle_charger_setup && chip->trickle_charger_reg) {
  2119			dev_dbg(ds1307->dev,
  2120				"writing trickle charger info 0x%x to 0x%x\n",
  2121				trickle_charger_setup, chip->trickle_charger_reg);
  2122			regmap_write(ds1307->regmap, chip->trickle_charger_reg,
  2123				     (u8)trickle_charger_setup);
  2124		}
  2125	
  2126	/*
  2127	 * For devices with no IRQ directly connected to the SoC, the RTC chip
  2128	 * can be forced as a wakeup source by stating that explicitly in
  2129	 * the device's .dts file using the "wakeup-source" boolean property.
  2130	 * If the "wakeup-source" property is set, don't request an IRQ.
  2131	 * This will guarantee the 'wakealarm' sysfs entry is available on the device,
  2132	 * if supported by the RTC.
  2133	 */
  2134		if (chip->alarm && device_property_read_bool(&client->dev, "wakeup-source"))
  2135			ds1307_can_wakeup_device = true;
  2136	
  2137		switch (ds1307->type) {
  2138		case ds_1337:
  2139		case ds_1339:
  2140		case ds_1341:
  2141		case ds_3231:
  2142			/* get registers that the "rtc" read below won't read... */
  2143			err = regmap_bulk_read(ds1307->regmap, DS1337_REG_CONTROL,
  2144					       regs, 2);
  2145			if (err) {
  2146				dev_dbg(ds1307->dev, "read error %d\n", err);
  2147				goto exit;
  2148			}
  2149	
  2150			/* oscillator off?  turn it on, so clock can tick. */
  2151			if (regs[0] & DS1337_BIT_nEOSC)
  2152				regs[0] &= ~DS1337_BIT_nEOSC;
  2153	
  2154			/*
  2155			 * Using IRQ or defined as wakeup-source?
  2156			 * Disable the square wave and both alarms.
  2157			 * For some variants, be sure alarms can trigger when we're
  2158			 * running on Vbackup (BBSQI/BBSQW)
  2159			 */
  2160			if (want_irq || ds1307_can_wakeup_device)
  2161				regs[0] |= DS1337_BIT_INTCN | chip->bbsqi_bit;
  2162	
  2163			regmap_write(ds1307->regmap, DS1337_REG_CONTROL,
  2164				     regs[0]);
  2165	
  2166			/* oscillator fault? warn */
  2167			if (regs[1] & DS1337_BIT_OSF) {
  2168				dev_warn(ds1307->dev, "SET TIME!\n");
  2169			}
  2170			break;
  2171	
  2172		case rx_8025:
  2173			err = regmap_bulk_read(ds1307->regmap,
  2174					       RX8025_REG_CTRL1 << 4 | 0x08, regs, 2);
  2175			if (err) {
  2176				dev_dbg(ds1307->dev, "read error %d\n", err);
  2177				goto exit;
  2178			}
  2179	
  2180			/* oscillator off?  turn it on, so clock can tick. */
  2181			if (!(regs[1] & RX8025_BIT_XST)) {
  2182				regs[1] |= RX8025_BIT_XST;
  2183				regmap_write(ds1307->regmap,
  2184					     RX8025_REG_CTRL2 << 4 | 0x08,
  2185					     regs[1]);
  2186				dev_warn(ds1307->dev,
  2187					 "oscillator stop detected - SET TIME!\n");
  2188			}
  2189	
  2190			if (regs[1] & RX8025_BIT_PON) {
  2191				regs[1] &= ~RX8025_BIT_PON;
  2192				regmap_write(ds1307->regmap,
  2193					     RX8025_REG_CTRL2 << 4 | 0x08,
  2194					     regs[1]);
  2195				dev_warn(ds1307->dev, "power-on detected\n");
  2196			}
  2197	
  2198			if (regs[1] & RX8025_BIT_VDET) {
  2199				regs[1] &= ~RX8025_BIT_VDET;
  2200				regmap_write(ds1307->regmap,
  2201					     RX8025_REG_CTRL2 << 4 | 0x08,
  2202					     regs[1]);
  2203				dev_warn(ds1307->dev, "voltage drop detected\n");
  2204			}
  2205	
  2206			/* make sure we are running in 24hour mode */
  2207			if (!(regs[0] & RX8025_BIT_2412)) {
  2208				u8 hour;
  2209	
  2210				/* switch to 24 hour mode */
  2211				regmap_write(ds1307->regmap,
  2212					     RX8025_REG_CTRL1 << 4 | 0x08,
  2213					     regs[0] | RX8025_BIT_2412);
  2214	
  2215				err = regmap_bulk_read(ds1307->regmap,
  2216						       RX8025_REG_CTRL1 << 4 | 0x08,
  2217						       regs, 2);
  2218				if (err) {
  2219					dev_dbg(ds1307->dev, "read error %d\n", err);
  2220					goto exit;
  2221				}
  2222	
  2223				/* correct hour */
  2224				hour = bcd2bin(regs[DS1307_REG_HOUR]);
  2225				if (hour == 12)
  2226					hour = 0;
  2227				if (regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
  2228					hour += 12;
  2229	
  2230				regmap_write(ds1307->regmap,
  2231					     DS1307_REG_HOUR << 4 | 0x08, hour);
  2232			}
  2233			break;
  2234		case ds_1388:
  2235			err = regmap_read(ds1307->regmap, DS1388_REG_CONTROL, &tmp);
  2236			if (err) {
  2237				dev_dbg(ds1307->dev, "read error %d\n", err);
  2238				goto exit;
  2239			}
  2240	
  2241			/* oscillator off?  turn it on, so clock can tick. */
  2242			if (tmp & DS1388_BIT_nEOSC) {
  2243				tmp &= ~DS1388_BIT_nEOSC;
  2244				regmap_write(ds1307->regmap, DS1388_REG_CONTROL, tmp);
  2245			}
  2246			break;
  2247		default:
  2248			break;
  2249		}
  2250	
  2251		/* read RTC registers */
  2252		err = regmap_bulk_read(ds1307->regmap, chip->offset, regs,
  2253				       sizeof(regs));
  2254		if (err) {
  2255			dev_dbg(ds1307->dev, "read error %d\n", err);
  2256			goto exit;
  2257		}
  2258	
  2259		if (ds1307->type == mcp794xx &&
  2260		    !(regs[DS1307_REG_WDAY] & MCP794XX_BIT_VBATEN)) {
  2261			regmap_write(ds1307->regmap, DS1307_REG_WDAY,
  2262				     regs[DS1307_REG_WDAY] |
  2263				     MCP794XX_BIT_VBATEN);
  2264		}
  2265	
  2266		tmp = regs[DS1307_REG_HOUR];
  2267		switch (ds1307->type) {
  2268		case ds_1340:
  2269		case m41t0:
  2270		case m41t00:
  2271		case m41t11:
  2272			/*
  2273			 * NOTE: ignores century bits; fix before deploying
  2274			 * systems that will run through year 2100.
  2275			 */
  2276			break;
  2277		case rx_8025:
  2278			break;
  2279		default:
  2280			if (!(tmp & DS1307_BIT_12HR))
  2281				break;
  2282	
  2283			/*
  2284			 * Be sure we're in 24 hour mode.  Multi-master systems
  2285			 * take note...
  2286			 */
  2287			tmp = bcd2bin(tmp & 0x1f);
  2288			if (tmp == 12)
  2289				tmp = 0;
  2290			if (regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
  2291				tmp += 12;
  2292			regmap_write(ds1307->regmap, chip->offset + DS1307_REG_HOUR,
  2293				     bin2bcd(tmp));
  2294		}
  2295	
  2296		ds1307->rtc = devm_rtc_allocate_device(ds1307->dev);
  2297		if (IS_ERR(ds1307->rtc))
  2298			return PTR_ERR(ds1307->rtc);
  2299	
  2300		if (want_irq || ds1307_can_wakeup_device)
  2301			device_set_wakeup_capable(ds1307->dev, true);
  2302		else
  2303			clear_bit(RTC_FEATURE_ALARM, ds1307->rtc->features);
  2304	
  2305		if (ds1307_can_wakeup_device && !want_irq) {
  2306			dev_info(ds1307->dev,
  2307				 "'wakeup-source' is set, request for an IRQ is disabled!\n");
  2308			/* We cannot support UIE mode if we do not have an IRQ line */
  2309			clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, ds1307->rtc->features);
  2310		}
  2311	
  2312		if (want_irq) {
  2313			err = devm_request_threaded_irq(ds1307->dev, client->irq, NULL,
  2314							chip->irq_handler ?: ds1307_irq,
  2315							IRQF_SHARED | IRQF_ONESHOT,
  2316							ds1307->name, ds1307);
  2317			if (err) {
  2318				client->irq = 0;
  2319				device_set_wakeup_capable(ds1307->dev, false);
  2320				clear_bit(RTC_FEATURE_ALARM, ds1307->rtc->features);
  2321				dev_err(ds1307->dev, "unable to request IRQ!\n");
  2322			} else {
  2323				dev_dbg(ds1307->dev, "got IRQ %d\n", client->irq);
  2324			}
  2325		}
  2326	
  2327		switch (ds1307->type) {
  2328		case rx_8901:
  2329			set_bit(RTC_FEATURE_BACKUP_SWITCH_MODE, ds1307->rtc->features);
  2330			break;
  2331		default:
> 2332		}
  2333	
  2334		ds1307->rtc->ops = chip->rtc_ops ?: &ds13xx_rtc_ops;
  2335		err = ds1307_add_frequency_test(ds1307);
  2336		if (err)
  2337			return err;
  2338	
  2339		err = devm_rtc_register_device(ds1307->rtc);
  2340		if (err)
  2341			return err;
  2342	
  2343		if (chip->nvram_size) {
  2344			struct nvmem_config nvmem_cfg = {
  2345				.name = "ds1307_nvram",
  2346				.word_size = 1,
  2347				.stride = 1,
  2348				.size = chip->nvram_size,
  2349				.reg_read = ds1307_nvram_read,
  2350				.reg_write = ds1307_nvram_write,
  2351				.priv = ds1307,
  2352			};
  2353	
  2354			devm_rtc_nvmem_register(ds1307->rtc, &nvmem_cfg);
  2355		}
  2356	
  2357		ds1307_hwmon_register(ds1307);
  2358		ds1307_clks_register(ds1307);
  2359		ds1307_wdt_register(ds1307);
  2360	
  2361		return 0;
  2362	
  2363	exit:
  2364		return err;
  2365	}
  2366	

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